640343643464 has 16 divisors (see below), whose sum is σ = 1372164950400. Its totient is φ = 274432990032.

The previous prime is 640343643449. The next prime is 640343643469. The reversal of 640343643464 is 464346343046.

It is not an unprimeable number, because it can be changed into a prime (640343643469) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5717353904 + ... + 5717354015.

It is an arithmetic number, because the mean of its divisors is an integer number (85760309400).

Almost surely, 2^640343643464 is an apocalyptic number.

It is an amenable number.

640343643464 is an abundant number, since it is smaller than the sum of its proper divisors (731821306936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640343643464 is a wasteful number, since it uses less digits than its factorization.

640343643464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11434707932 (or 11434707928 counting only the distinct ones).

The product of its (nonzero) digits is 5971968, while the sum is 47.

The spelling of 640343643464 in words is "six hundred forty billion, three hundred forty-three million, six hundred forty-three thousand, four hundred sixty-four".